A sleep deficit of less than one hour of nightly sleep, over the course of six days, can cause children with attention deficit hyperactivity disorder (ADHD) to be wary and less attentive.

Researchers writing in the journal Sleep discovered even moderate reductions in sleep duration can affect an ADHD child’s brain and their neurobehavioral functioning, which in turn appears to have a negative impact on their academic performance.

Investigators discovered an average nightly sleep loss of about 55 minutes for six nights was associated with deteriorating performance including inattention, omission and depressed reaction time in children with attention deficit disorder.

“Moderate sleep restriction leads to a detectable negative impact on the neurobehavioral functioning of children with ADHD and healthy controls, leading to a clinical level of impairment in children with ADHD,” said lead author and principal investigator Reut Gruber, Ph.D.

The National Institute of Mental Health reports that ADHD is one of the most common childhood disorders and is characterized by inattention, hyperactivity and impulsivity. To be diagnosed with the disorder, a child must have symptoms for 6 months or more and to a degree that is greater than other children of the same age.

The study involved 43 children, 11 with ADHD and 32 controls. They had a mean age of about 9 years. After their baseline sleep was monitored for six nights, children were asked to eliminate one hour of nightly sleep for six consecutive nights by going to sleep one hour later than usual.

During the baseline and experimental periods, sleep was monitored at home using an actigraph, a computerized device that looks like a wristwatch. Mean nightly sleep time dropped from 487.75 minutes at baseline to 433.07 minutes for the ADHD group, and from 478.81 minutes at baseline to 444.67 minutes for the control group.

“The reduction in sleep duration in our study was modest and similar to the sleep deprivation that might occur in daily life,” Gruber said.

“Thus, even small changes in dinner time, computer time, or staying up to do homework could result in poorer neurobehavioral functioning the following day and affect sustained attention and vigilance, which are essential for optimal academic performance.”

Gruber added that the problem of inadequate sleep in students needs to be prioritized and addressed by the educational system.

“An important implication of the present study is that investments in programs that aim to decrease sleep deprivation may lead to improvements in neurobehavioral functioning and academic performance,” she said.